<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="generator" content="Asciidoctor 2.0.26">
<link rel="icon" type="image/svg" href="../../../../_docs/_Assets/Logo.svg">
<title>Value conversion sample</title>
<style>
@import url(https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css);

:root {
    --background: #fff;
    --black-color: #000;
    --background-yellow: #ff0;
    --border: #c0c0c0;
    --gray-color: #6c818f;
    --link-color-default: var(--accent-primary-color);
    --foreground-color: #222222;
    --accent-primary-color: #3578e5;
    --accent-secondary-color: #102445;
    --border2: #dddddd;
    --block-quote-color: #748590;
    --pre-background-color: #f2f2f2;
    --dark-gray-color: #333333;
    --kdb-background-color: #F7F7F7;
    --header-color: var(--accent-primary-color);
    --link-hover-color: #102445;
    --toc-border-color: #d9d9d9;
    --exampleblock-border-color: #e6e6e6;
    --em-color: #373737;
    --admotion-background-color: #e6e6e6;
    --sidebar-background-color: #e8ecef;
    --border-radius-default: 6px;
}

/* normalize.css v2.1.1 | MIT License | git.io/normalize */
/* ========================================================================== HTML5 display definitions ========================================================================== */
/** Correct `block` display not defined in IE 8/9. */
article, aside, details, figcaption, figure, footer, header, hgroup, main, nav, section, summary {
    display: block;
}

/** Correct `inline-block` display not defined in IE 8/9. */
audio, canvas, video {
    display: inline-block;
}

/** Prevent modern browsers from displaying `audio` without controls. Remove excess height in iOS 5 devices. */
audio:not([controls]) {
    display: none;
    height: 0;
}

/** Address styling not present in IE 8/9. */
[hidden] {
    display: none;
}

/* ========================================================================== Base ========================================================================== */
/** 1. Prevent system color scheme's background color being used in Firefox, IE, and Opera. 2. Prevent system color scheme's text color being used in Firefox, IE, and Opera. 3. Set default font family to sans-serif. 4. Prevent iOS text size adjust after orientation change, without disabling user zoom. */
html {
    background: var(--background); /* 1 */
    color: var(--black-color); /* 2 */
    font-family: sans-serif; /* 3 */
    -ms-text-size-adjust: 100%; /* 4 */
    -webkit-text-size-adjust: 100%; /* 4 */
}

/** Remove default margin. */
body {
    margin: 0;
}

/* ========================================================================== Links ========================================================================== */
/** Address `outline` inconsistency between Chrome and other browsers. */
a:focus {
    outline: thin dotted;
}

/** Improve readability when focused and also mouse hovered in all browsers. */
a:active, a:hover {
    outline: 0;
}

/* ========================================================================== Typography ========================================================================== */
/** Address variable `h1` font-size and margin within `section` and `article` contexts in Firefox 4+, Safari 5, and Chrome. */
h1 {
    font-size: 2em;
    margin: 0.67em 0;
}

/** Address styling not present in IE 8/9, Safari 5, and Chrome. */
abbr[title] {
    border-bottom: 1px dotted;
}

/** Address style set to `bolder` in Firefox 4+, Safari 5, and Chrome. */
b, strong {
    font-weight: bold;
}

/** Address styling not present in Safari 5 and Chrome. */
dfn {
    font-style: italic;
}

/** Address differences between Firefox and other browsers. */
hr {
    -moz-box-sizing: content-box;
    box-sizing: content-box;
    height: 0;
}

/** Address styling not present in IE 8/9. */
mark {
    background: var(--background-yellow);
    color: var(--black-color);
}

/** Correct font family set oddly in Safari 5 and Chrome. */
code, kbd, pre, samp {
    font-family: monospace, serif;
    font-size: 1em;
}

/** Improve readability of pre-formatted text in all browsers. */
pre {
    white-space: pre-wrap;
}

/** Set consistent quote types. */
q {
    quotes: "\201C" "\201D" "\2018" "\2019";
}

/** Address inconsistent and variable font size in all browsers. */
small {
    font-size: 80%;
}

/** Prevent `sub` and `sup` affecting `line-height` in all browsers. */
sub, sup {
    font-size: 75%;
    line-height: 0;
    position: relative;
    vertical-align: baseline;
}

sup {
    top: -0.5em;
}

sub {
    bottom: -0.25em;
}

/* ========================================================================== Embedded content ========================================================================== */
/** Remove border when inside `a` element in IE 8/9. */
img {
    border: 0;
}

/** Correct overflow displayed oddly in IE 9. */
svg:not(:root) {
    overflow: hidden;
}

/* ========================================================================== Figures ========================================================================== */
/** Address margin not present in IE 8/9 and Safari 5. */
figure {
    margin: 0;
}

/* ========================================================================== Forms ========================================================================== */
/** Define consistent border, margin, and padding. */
fieldset {
    border: 1px solid var(--border);
    margin: 0 2px;
    padding: 0.35em 0.625em 0.75em;
}

/** 1. Correct `color` not being inherited in IE 8/9. 2. Remove padding so people aren't caught out if they zero out fieldsets. */
legend {
    border: 0; /* 1 */
    padding: 0; /* 2 */
}

/** 1. Correct font family not being inherited in all browsers. 2. Correct font size not being inherited in all browsers. 3. Address margins set differently in Firefox 4+, Safari 5, and Chrome. */
button, input, select, textarea {
    font-family: inherit; /* 1 */
    font-size: 100%; /* 2 */
    margin: 0; /* 3 */
}

/** Address Firefox 4+ setting `line-height` on `input` using `!important` in the UA stylesheet. */
button, input {
    line-height: normal;
}

/** Address inconsistent `text-transform` inheritance for `button` and `select`. All other form control elements do not inherit `text-transform` values. Correct `button` style inheritance in Chrome, Safari 5+, and IE 8+. Correct `select` style inheritance in Firefox 4+ and Opera. */
button, select {
    text-transform: none;
}

/** 1. Avoid the WebKit bug in Android 4.0.* where (2) destroys native `audio` and `video` controls. 2. Correct inability to style clickable `input` types in iOS. 3. Improve usability and consistency of cursor style between image-type `input` and others. */
button, html input[type="button"], input[type="reset"], input[type="submit"] {
    -webkit-appearance: button; /* 2 */
    cursor: pointer; /* 3 */
}

/** Re-set default cursor for disabled elements. */
button[disabled], html input[disabled] {
    cursor: default;
}

/** 1. Address box sizing set to `content-box` in IE 8/9. 2. Remove excess padding in IE 8/9. */
input[type="checkbox"], input[type="radio"] {
    box-sizing: border-box; /* 1 */
    padding: 0; /* 2 */
}

/** 1. Address `appearance` set to `searchfield` in Safari 5 and Chrome. 2. Address `box-sizing` set to `border-box` in Safari 5 and Chrome (include `-moz` to future-proof). */
input[type="search"] {
    -webkit-appearance: textfield; /* 1 */
    -moz-box-sizing: content-box;
    -webkit-box-sizing: content-box; /* 2 */
    box-sizing: content-box;
}

/** Remove inner padding and search cancel button in Safari 5 and Chrome on OS X. */
input[type="search"]::-webkit-search-cancel-button, input[type="search"]::-webkit-search-decoration {
    -webkit-appearance: none;
}

/** Remove inner padding and border in Firefox 4+. */
button::-moz-focus-inner, input::-moz-focus-inner {
    border: 0;
    padding: 0;
}

/** 1. Remove default vertical scrollbar in IE 8/9. 2. Improve readability and alignment in all browsers. */
textarea {
    overflow: auto; /* 1 */
    vertical-align: top; /* 2 */
}

/* ========================================================================== Tables ========================================================================== */
/** Remove most spacing between table cells. */
table {
    border-collapse: collapse;
    border-spacing: 0;
}

*, *:before, *:after {
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
    box-sizing: border-box;
}

html, body {
    font-size: 100%;
}

body {
    background: white;
    color: var(--foreground-color);
    padding: 0;
    margin: 0;
    font-family: "Helvetica Neue", "Helvetica", Helvetica, Arial, sans-serif;
    font-weight: normal;
    font-style: normal;
    line-height: 1;
    position: relative;
    cursor: auto;
}

a:hover {
    cursor: pointer;
}

a:focus {
    outline: none;
}

img, object, embed {
    max-width: 100%;
    height: auto;
}

object, embed {
    height: 100%;
}

img {
    -ms-interpolation-mode: bicubic;
}

#map_canvas img, #map_canvas embed, #map_canvas object, .map_canvas img, .map_canvas embed, .map_canvas object {
    max-width: none !important;
}

.left {
    float: left !important;
}

.right {
    float: right !important;
}

.text-left {
    text-align: left !important;
}

.text-right {
    text-align: right !important;
}

.text-center {
    text-align: center !important;
}

.text-justify {
    text-align: justify !important;
}

.hide {
    display: none;
}

.antialiased, body {
    -webkit-font-smoothing: antialiased;
}

img {
    display: inline-block;
    vertical-align: middle;
}

textarea {
    height: auto;
    min-height: 50px;
}

select {
    width: 100%;
}

p.lead, .paragraph.lead > p, #preamble > .sectionbody > .paragraph:first-of-type p {
    font-size: 1.21875em;
    line-height: 1.6;
}

.subheader, #content #toctitle, .admonitionblock td.content > .title, .exampleblock > .title, .imageblock > .title, .videoblock > .title, .listingblock > .title, .literalblock > .title, .openblock > .title, .paragraph > .title, .quoteblock > .title, .sidebarblock > .title, .tableblock > .title, .verseblock > .title, .dlist > .title, .olist > .title, .ulist > .title, .qlist > .title, .hdlist > .title, .tableblock > caption {
    line-height: 1.4;
    color: var(--accent-primary-color);
    font-weight: 300;
    margin-top: 0.5em;
    margin-bottom: 0.5em;
}

/* Typography resets */
div, dl, dt, dd, ul, ol, li, h1, h2, h3, #toctitle, .sidebarblock > .content > .title, h4, h5, h6, pre, form, p, blockquote, th, td {
    margin: 0;
    /*padding: 0;*/
    direction: ltr;
}

/* Default Link Styles */
a {
    color: var(--link-color-default);
    text-decoration: none;
    line-height: inherit;
}

a:hover, a:focus {
    color: var(--header-color);
}

a img {
    border: none;
}

/* Default paragraph styles */
p {
    font-family: inherit;
    font-weight: normal;
    font-size: 1em;
    line-height: 1.5;
    margin-bottom: 1.25em;
    text-rendering: optimizeLegibility;
}

p aside {
    font-size: 0.875em;
    line-height: 1.35;
    font-style: italic;
}

/* Default header styles */
h1, h2, h3, #toctitle, .sidebarblock > .content > .title, h4, h5, h6 {
    font-family: ff-meta-web-pro-1, ff-meta-web-pro-2, Arial, "Helvetica Neue", sans-serif;
    font-weight: bold;
    font-style: normal;
    color: var(--accent-primary-color);
    text-rendering: optimizeLegibility;
    margin-top: 1em;
    margin-bottom: 0.5em;
    line-height: 1.2125em;
}

h1 small, h2 small, h3 small, #toctitle small, .sidebarblock > .content > .title small, h4 small, h5 small, h6 small {
    font-size: 60%;
    color: var(--accent-secondary-color);
    line-height: 0;
}

h1 {
    font-size: 2.125em;
}

h2 {
    font-size: 1.6875em;
}

h3, #toctitle, .sidebarblock > .content > .title {
    font-size: 1.375em;
}

h4 {
    font-size: 1.125em;
}

h5 {
    font-size: 1.125em;
}

h6 {
    font-size: 1em;
}

hr {
    border: solid var(--border2);
    border-width: 1px 0 0;
    clear: both;
    margin: 1.25em 0 1.1875em;
    height: 0;
}

/* Helpful Typography Defaults */
em, i {
    font-style: italic;
    line-height: inherit;
}

strong, b {
    font-weight: bold;
    line-height: inherit;
}

small {
    font-size: 60%;
    line-height: inherit;
}

code {
    font-family: "Consolas", "Deja Vu Sans Mono", "Bitstream Vera Sans Mono", monospace;
    font-weight: normal;
    color: var(--link-color-default);
}

/* Lists */
ul, ol, dl {
    font-size: 1em;
    line-height: 1.5;
    margin-bottom: 1.25em;
    list-style-position: outside;
    font-family: inherit;
}

ul, ol {
    margin-left: 0;
}

/* Unordered Lists */
ul li ul, ul li ol {
    margin-left: 1.25em;
    margin-bottom: 0;
    font-size: 1em; /* Override nested font-size change */
}

ul.square li ul, ul.circle li ul, ul.disc li ul {
    list-style: inherit;
}

ul.square {
    list-style-type: square;
}

ul.circle {
    list-style-type: circle;
}

ul.disc {
    list-style-type: disc;
}

ul.no-bullet {
    list-style: none;
}

/* Ordered Lists */
ol li ul, ol li ol {
    margin-left: 1.25em;
    margin-bottom: 0;
}

/* Definition Lists */
dl dt {
    margin-bottom: 0.3em;
    font-weight: bold;
}

dl dd {
    margin-bottom: 0.75em;
}

/* Abbreviations */
abbr, acronym {
    text-transform: uppercase;
    font-size: 90%;
    color: black;
    border-bottom: 1px dotted var(--border2);
    cursor: help;
}

abbr {
    text-transform: none;
}

/* Blockquotes */
blockquote {
    margin: 0 0 1.25em;
    padding: 0.5625em 1.25em 0 1.1875em;
    border-left: 1px solid var(--border2);
}

blockquote cite {
    display: block;
    font-size: 0.8125em;
    color: var(--block-quote-color);
}

blockquote cite:before {
    content: "\2014 \0020";
}

blockquote cite a, blockquote cite a:visited {
    color: var(--block-quote-color);
}

blockquote, blockquote p {
    line-height: 1.5;
    color: var(--accent-secondary-color);
}

/* Microformats */
.vcard {
    display: inline-block;
    margin: 0 0 1.25em 0;
    border: 1px solid var(--border2);
    padding: 0.625em 0.75em;
}

.vcard li {
    margin: 0;
    display: block;
}

.vcard .fn {
    font-weight: bold;
    font-size: 0.9375em;
}

.vevent .summary {
    font-weight: bold;
}

.vevent abbr {
    cursor: auto;
    text-decoration: none;
    font-weight: bold;
    border: none;
    padding: 0 0.0625em;
}

@media only screen and (min-width: 768px) {
    h1, h2, h3, #toctitle, .sidebarblock > .content > .title, h4, h5, h6 {
        line-height: 1.4;
    }

    h1 {
        font-size: 2.75em;
    }

    h2 {
        font-size: 2.3125em;
    }

    h3, #toctitle, .sidebarblock > .content > .title {
        font-size: 1.6875em;
    }

    h4 {
        font-size: 1.4375em;
    }
}

/* Print styles.  Inlined to avoid required HTTP connection: www.phpied.com/delay-loading-your-print-css/ Credit to Paul Irish and HTML5 Boilerplate (html5boilerplate.com)
*/
.print-only {
    display: none !important;
}

@media print {
    * {
        background: transparent !important;
        color: var(--black-color) !important; /* Black prints faster: h5bp.com/s */
        box-shadow: none !important;
        text-shadow: none !important;
    }

    a, a:visited {
        text-decoration: underline;
    }

    a[href]:after {
        content: " (" attr(href) ")";
    }

    abbr[title]:after {
        content: " (" attr(title) ")";
    }

    .ir a:after, a[href^="javascript:"]:after, a[href^="#"]:after {
        content: "";
    }

    pre, blockquote {
        border: 1px solid #999;
        page-break-inside: avoid;
    }

    thead {
        display: table-header-group; /* h5bp.com/t */
    }

    tr, img {
        page-break-inside: avoid;
    }

    img {
        max-width: 100% !important;
    }

    @page {
        margin: 0.5cm;
    }

    p, h2, h3, #toctitle, .sidebarblock > .content > .title {
        orphans: 3;
        widows: 3;
    }

    h2, h3, #toctitle, .sidebarblock > .content > .title {
        page-break-after: avoid;
    }

    .hide-on-print {
        display: none !important;
    }

    .print-only {
        display: block !important;
    }

    .hide-for-print {
        display: none !important;
    }

    .show-for-print {
        display: inherit !important;
    }
}

/* Tables */
table {
    background: white;
    margin-bottom: 1.25em;
    border: solid 0 var(--border2);
}

table thead, table tfoot {
    background: none;
    font-weight: bold;
}

table thead tr th, table thead tr td, table tfoot tr th, table tfoot tr td {
    padding: 1px 8px 1px 5px;
    font-size: 1em;
    color: var(--foreground-color);
    text-align: left;
}

table tr th, table tr td {
    padding: 1px 8px 1px 5px;
    font-size: 1em;
    color: var(--foreground-color);
}

table tr.even, table tr.alt, table tr:nth-of-type(even) {
    background: none;
}

table thead tr th, table tfoot tr th, table tbody tr td, table tr td, table tfoot tr td {
    display: table-cell;
    line-height: 1.5;
}

.clearfix:before, .clearfix:after, .float-group:before, .float-group:after {
    content: " ";
    display: table;
}

.clearfix:after, .float-group:after {
    clear: both;
}

*:not(pre) > code {
    font-size: 0.95em;
    padding: 0;
    white-space: nowrap;
    background-color: var(--pre-background-color);
    border: 0 solid var(--border2);
    -webkit-border-radius: var(--border-radius-default);
    border-radius: var(--border-radius-default);
    text-shadow: none;
}

pre, pre > code {
    line-height: 1.2;
    color: inherit;
    font-family: "Consolas", "Deja Vu Sans Mono", "Bitstream Vera Sans Mono", monospace;
    font-weight: normal;
}

kbd.keyseq {
    color: var(--dark-gray-color);
}

kbd:not(.keyseq) {
    display: inline-block;
    color: black;
    font-size: 0.75em;
    line-height: 1.4;
    background-color: var(--kdb-background-color);
    border: 1px solid #ccc;
    -webkit-border-radius: 3px;
    border-radius: 3px;
    -webkit-box-shadow: 0 1px 0 rgba(0, 0, 0, 0.2), 0 0 0 2px white inset;
    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.2), 0 0 0 2px white inset;
    margin: -0.15em 0.15em 0 0.15em;
    padding: 0.2em 0.6em 0.2em 0.5em;
    vertical-align: middle;
    white-space: nowrap;
}

kbd kbd:first-child {
    margin-left: 0;
}

kbd kbd:last-child {
    margin-right: 0;
}

.menuseq, .menu {
    color: black;
}

p a > code:hover {
    color: var(--link-hover-color);
}

#header, #content, #footnotes, #footer {
    width: 100%;
    margin-left: auto;
    margin-right: auto;
    margin-top: 0;
    margin-bottom: 0;
    max-width: 62.5em;
    *zoom: 1;
    position: relative;
    padding-left: 0.9375em;
    padding-right: 0.9375em;
}

#header:before, #header:after, #content:before, #content:after, #footnotes:before, #footnotes:after, #footer:before, #footer:after {
    content: " ";
    display: table;
}

#header:after, #content:after, #footnotes:after, #footer:after {
    clear: both;
}

#header {
    margin-bottom: 2.5em;
}

#header > h1 {
    color: var(--header-color);
    font-weight: bold;
    border-bottom: 1px solid var(--border2);
    margin-bottom: -28px;
    padding-bottom: 32px;
}

#header span {
    color: var(--accent-secondary-color);
}

#header #revnumber {
    text-transform: capitalize;
}

#header br {
    display: none;
}

#header br + span {
    padding-left: 3px;
}

#header br + span:before {
    content: "\2013 \0020";
}

#header br + span.author {
    padding-left: 0;
}

#header br + span.author:before {
    content: ", ";
}

#toc {
    border-bottom: 1px solid var(--border2);
    padding-bottom: 1.25em;
}

#toc > ul {
    margin-left: 0.25em;
}

#toc ul.sectlevel0 > li > a {
    font-style: italic;
}

#toc ul.sectlevel0 ul.sectlevel1 {
    margin-left: 0;
    margin-top: 0.5em;
    margin-bottom: 0.5em;
}

#toc ul {
    list-style-type: none;
}

#toctitle {
    color: var(--accent-primary-color);
}

@media only screen and (min-width: 1280px) {
    body.toc2 {
        padding-left: 20em;
    }

    #toc.toc2 {
        position: fixed;
        width: 20em;
        left: 0;
        top: 0;
        border-right: 1px solid var(--border2);
        border-bottom: 0;
        z-index: 1000;
        padding: 44px 1em 1em;
        height: 100%;
        overflow: auto;
    }

    #toc.toc2 > ul {
        padding-left: 1em;
    }

    #toc.toc2 #toctitle {
        margin-top: 0;
    }

    #toc.toc2 > ul {
        font-size: .95em;
    }

    #toc.toc2 ul ul {
        margin-left: 0;
        padding-left: 1.25em;
    }

    #toc.toc2 ul.sectlevel0 ul.sectlevel1 {
        padding-left: 0;
        margin-top: 0.5em;
        margin-bottom: 0.5em;
    }

    body.toc2.toc-right {
        padding-left: 0;
        padding-right: 20em;
    }

    body.toc2.toc-right #toc.toc2 {
        border-right: 0;
        border-left: 1px solid var(--border2);
        left: auto;
        right: 0;
    }
}

#content #toc {
    border-style: solid;
    border-width: 1px;
    border-color: var(--toc-border-color);
    margin-bottom: 1.25em;
    padding: 1.25em;
    background: var(--pre-background-color);
    border-width: 0;
    -webkit-border-radius: var(--border-radius-default);
    border-radius: var(--border-radius-default);
}

#content #toc > :first-child {
    margin-top: 0;
}

#content #toc > :last-child {
    margin-bottom: 0;
}

#content #toc a {
    color: var(--gray-color);
    text-decoration: none;
}

#content #toctitle {
    font-weight: bold;
    font-family: ff-meta-web-pro-1, ff-meta-web-pro-2, Arial, "Helvetica Neue", sans-serif;
    font-size: 1em;
    padding-left: 0.125em;
}

#footer {
    max-width: 100%;
    background-color: black;
    padding: 1.25em;
}

#footer-text {
    color: white;
    line-height: 1.35;
}

.sect1 {
    padding-bottom: 1.25em;
}

.sect1 + .sect1 {
    border-top: 1px solid var(--border2);
}

#content h1 > a.anchor, h2 > a.anchor, h3 > a.anchor, #toctitle > a.anchor, .sidebarblock > .content > .title > a.anchor, h4 > a.anchor, h5 > a.anchor, h6 > a.anchor {
    position: absolute;
    width: 1em;
    margin-left: -1em;
    display: block;
    text-decoration: none;
    visibility: hidden;
    text-align: center;
    font-weight: normal;
}

#content h1 > a.anchor:before, h2 > a.anchor:before, h3 > a.anchor:before, #toctitle > a.anchor:before, .sidebarblock > .content > .title > a.anchor:before, h4 > a.anchor:before, h5 > a.anchor:before, h6 > a.anchor:before {
    content: '\00A7';
    font-size: .85em;
    vertical-align: text-top;
    display: block;
    margin-top: 0.05em;
}

#content h1:hover > a.anchor, #content h1 > a.anchor:hover, h2:hover > a.anchor, h2 > a.anchor:hover, h3:hover > a.anchor, #toctitle:hover > a.anchor, .sidebarblock > .content > .title:hover > a.anchor, h3 > a.anchor:hover, #toctitle > a.anchor:hover, .sidebarblock > .content > .title > a.anchor:hover, h4:hover > a.anchor, h4 > a.anchor:hover, h5:hover > a.anchor, h5 > a.anchor:hover, h6:hover > a.anchor, h6 > a.anchor:hover {
    visibility: visible;
}

#content h1 > a.link, h2 > a.link, h3 > a.link, #toctitle > a.link, .sidebarblock > .content > .title > a.link, h4 > a.link, h5 > a.link, h6 > a.link {
    color: var(--accent-primary-color);
    text-decoration: none;
}

#content h1 > a.link:hover, h2 > a.link:hover, h3 > a.link:hover, #toctitle > a.link:hover, .sidebarblock > .content > .title > a.link:hover, h4 > a.link:hover, h5 > a.link:hover, h6 > a.link:hover {
    color: var(--link-hover-color);
}

.imageblock, .literalblock, .listingblock, .verseblock, .videoblock {
    margin-bottom: 1.25em;
}

.admonitionblock td.content > .title, .exampleblock > .title, .imageblock > .title, .videoblock > .title, .listingblock > .title, .literalblock > .title, .openblock > .title, .paragraph > .title, .quoteblock > .title, .sidebarblock > .title, .tableblock > .title, .verseblock > .title, .dlist > .title, .olist > .title, .ulist > .title, .qlist > .title, .hdlist > .title {
    text-align: left;
    font-weight: bold;
}

.tableblock > caption {
    text-align: left;
    font-weight: bold;
    white-space: nowrap;
    overflow: visible;
    max-width: 0;
}

table.tableblock #preamble > .sectionbody > .paragraph:first-of-type p {
    font-size: inherit;
}

.admonitionblock > table {
    border: 0;
    background: none;
    width: 100%;
}

.admonitionblock > table td.icon {
    text-align: center;
    width: 60px;
    padding: 0;
    font-size: 1.5em;
}

.admonitionblock > table td.icon img {
    max-width: none;
}

.admonitionblock > table td.icon .title {
    font-weight: bold;
    text-transform: uppercase;
}

.admonitionblock > table td.content {
    /*padding-left: 1.125em;*/
    /*padding-right: 1.25em;*/
    border-left: 1px solid var(--border2);
    color: var(--accent-secondary-color);
}

.admonitionblock > table td.content > :last-child > :last-child {
    margin-bottom: 0;
}

.exampleblock > .content {
    border-style: solid;
    border-width: 1px;
    border-color: var(--exampleblock-border-color);
    margin-bottom: 1.25em;
    padding: 1.25em;
    background: white;
    -webkit-border-radius: var(--border-radius-default);
    border-radius: var(--border-radius-default);
}

.exampleblock > .content > :first-child {
    margin-top: 0;
}

.exampleblock > .content > :last-child {
    margin-bottom: 0;
}

.exampleblock > .content h1, .exampleblock > .content h2, .exampleblock > .content h3, .exampleblock > .content #toctitle, .sidebarblock.exampleblock > .content > .title, .exampleblock > .content h4, .exampleblock > .content h5, .exampleblock > .content h6, .exampleblock > .content p {
    color: var(--dark-gray-color);
}

.exampleblock > .content h1, .exampleblock > .content h2, .exampleblock > .content h3, .exampleblock > .content #toctitle, .sidebarblock.exampleblock > .content > .title, .exampleblock > .content h4, .exampleblock > .content h5, .exampleblock > .content h6 {
    line-height: 1;
    margin-bottom: 0.625em;
}

.exampleblock > .content h1.subheader, .exampleblock > .content h2.subheader, .exampleblock > .content h3.subheader, .exampleblock > .content .subheader#toctitle, .sidebarblock.exampleblock > .content > .subheader.title, .exampleblock > .content h4.subheader, .exampleblock > .content h5.subheader, .exampleblock > .content h6.subheader {
    line-height: 1.4;
}

.exampleblock.result > .content {
    -webkit-box-shadow: 0 1px 8px var(--toc-border-color);
    box-shadow: 0 1px 8px var(--toc-border-color);
}

.sidebarblock {
    border-style: solid;
    border-width: 1px;
    border-color: var(--toc-border-color);
    margin-bottom: 1.25em;
    padding: 1.25em;
    background: var(--pre-background-color);
    -webkit-border-radius: var(--border-radius-default);
    border-radius: var(--border-radius-default);
}

.sidebarblock > :first-child {
    margin-top: 0;
}

.sidebarblock > :last-child {
    margin-bottom: 0;
}

.sidebarblock h1, .sidebarblock h2, .sidebarblock h3, .sidebarblock #toctitle, .sidebarblock > .content > .title, .sidebarblock h4, .sidebarblock h5, .sidebarblock h6, .sidebarblock p {
    color: var(--dark-gray-color);
}

.sidebarblock h1, .sidebarblock h2, .sidebarblock h3, .sidebarblock #toctitle, .sidebarblock > .content > .title, .sidebarblock h4, .sidebarblock h5, .sidebarblock h6 {
    line-height: 1;
    margin-bottom: 0.625em;
}

.sidebarblock h1.subheader, .sidebarblock h2.subheader, .sidebarblock h3.subheader, .sidebarblock .subheader#toctitle, .sidebarblock > .content > .subheader.title, .sidebarblock h4.subheader, .sidebarblock h5.subheader, .sidebarblock h6.subheader {
    line-height: 1.4;
}

.sidebarblock > .content > .title {
    color: var(--gray-color);
    margin-top: 0;
    line-height: 1.5;
}

.exampleblock > .content > :last-child > :last-child, .exampleblock > .content .olist > ol > li:last-child > :last-child, .exampleblock > .content .ulist > ul > li:last-child > :last-child, .exampleblock > .content .qlist > ol > li:last-child > :last-child, .sidebarblock > .content > :last-child > :last-child, .sidebarblock > .content .olist > ol > li:last-child > :last-child, .sidebarblock > .content .ulist > ul > li:last-child > :last-child, .sidebarblock > .content .qlist > ol > li:last-child > :last-child {
    margin-bottom: 0;
}

.literalblock > .content pre, .listingblock > .content pre {
    background: #eeeeee;
    border-width: 1px;
    border-style: solid;
    border-color: #cccccc;
    -webkit-border-radius: var(--border-radius-default);
    border-radius: var(--border-radius-default);
    padding: 0.5em;
    word-wrap: break-word;
}

.literalblock > .content pre.nowrap, .listingblock > .content pre.nowrap {
    overflow-x: auto;
    white-space: pre;
    word-wrap: normal;
}

.literalblock > .content pre > code, .listingblock > .content pre > code {
    display: block;
}

@media only screen {
    .literalblock > .content pre, .listingblock > .content pre {
        font-size: 0.76em;
    }
}

@media only screen and (min-width: 768px) {
    .literalblock > .content pre, .listingblock > .content pre {
        font-size: 0.855em;
    }
}

@media only screen and (min-width: 1280px) {
    .literalblock > .content pre, .listingblock > .content pre {
        font-size: 0.95em;
    }
}

.listingblock > .content {
    position: relative;
}

.listingblock:hover code[class*=" language-"]:before {
    text-transform: uppercase;
    font-size: 0.9em;
    color: #999;
    position: absolute;
    top: 0.375em;
    right: 0.375em;
}

.listingblock:hover code.asciidoc:before {
    content: "asciidoc";
}

.listingblock:hover code.clojure:before {
    content: "clojure";
}

.listingblock:hover code.css:before {
    content: "css";
}

.listingblock:hover code.groovy:before {
    content: "groovy";
}

.listingblock:hover code.html:before {
    content: "html";
}

.listingblock:hover code.java:before {
    content: "java";
}

.listingblock:hover code.javascript:before {
    content: "javascript";
}

.listingblock:hover code.python:before {
    content: "python";
}

.listingblock:hover code.ruby:before {
    content: "ruby";
}

.listingblock:hover code.scss:before {
    content: "scss";
}

.listingblock:hover code.xml:before {
    content: "xml";
}

.listingblock:hover code.yaml:before {
    content: "yaml";
}

.listingblock.terminal pre .command:before {
    content: attr(data-prompt);
    padding-right: 0.5em;
    color: #999;
}

.listingblock.terminal pre .command:not([data-prompt]):before {
    content: '$';
}

table.pyhltable {
    border: 0;
    margin-bottom: 0;
}

table.pyhltable td {
    vertical-align: top;
    padding-top: 0;
    padding-bottom: 0;
}

table.pyhltable td.code {
    padding-left: .75em;
    padding-right: 0;
}

.highlight.pygments .lineno, table.pyhltable td:not(.code) {
    color: #999;
    padding-left: 0;
    padding-right: .5em;
    border-right: 1px solid var(--border2);
}

.highlight.pygments .lineno {
    display: inline-block;
    margin-right: .25em;
}

table.pyhltable .linenodiv {
    background-color: transparent !important;
    padding-right: 0 !important;
}

.quoteblock {
    margin: 0 0 1.25em;
    padding: 0.5625em 1.25em 0 1.1875em;
    border-left: 1px solid var(--border2);
}

.quoteblock blockquote {
    margin: 0 0 1.25em 0;
    padding: 0 0 0.5625em 0;
    border: 0;
}

.quoteblock blockquote > .paragraph:last-child p {
    margin-bottom: 0;
}

.quoteblock .attribution {
    margin-top: -.25em;
    padding-bottom: 0.5625em;
    font-size: 0.8125em;
    color: var(--block-quote-color);
}

.quoteblock .attribution br {
    display: none;
}

.quoteblock .attribution cite {
    display: block;
    margin-bottom: 0.625em;
}

table thead th, table tfoot th {
    font-weight: bold;
}

table.tableblock.grid-all {
    border-collapse: separate;
    border-spacing: 1px;
    -webkit-border-radius: var(--border-radius-default);
    border-radius: var(--border-radius-default);
    border-top: 0 solid var(--border2);
    border-bottom: 0 solid var(--border2);
}

table.tableblock.frame-topbot, table.tableblock.frame-none {
    border-left: 0;
    border-right: 0;
}

table.tableblock.frame-sides, table.tableblock.frame-none {
    border-top: 0;
    border-bottom: 0;
}

table.tableblock td .paragraph:last-child p, table.tableblock td > p:last-child {
    margin-bottom: 0;
}

th.tableblock.halign-left, td.tableblock.halign-left {
    text-align: left;
}

th.tableblock.halign-right, td.tableblock.halign-right {
    text-align: right;
}

th.tableblock.halign-center, td.tableblock.halign-center {
    text-align: center;
}

th.tableblock.valign-top, td.tableblock.valign-top {
    vertical-align: top;
}

th.tableblock.valign-bottom, td.tableblock.valign-bottom {
    vertical-align: bottom;
}

th.tableblock.valign-middle, td.tableblock.valign-middle {
    vertical-align: middle;
}

p.tableblock.header {
    color: var(--foreground-color);
    font-weight: bold;
}

td > div.verse {
    white-space: pre;
}

ol {
    margin-left: 0.25em;
}

ul li ol {
    margin-left: 0;
}

dl dd {
    margin-left: 1.125em;
}

dl dd:last-child, dl dd:last-child > :last-child {
    margin-bottom: 0;
}

ol > li p, ul > li p, ul dd, ol dd, .olist .olist, .ulist .ulist, .ulist .olist, .olist .ulist {
    margin-bottom: 0.625em;
}

ul.unstyled, ol.unnumbered, ul.checklist, ul.none {
    list-style-type: none;
}

ul.unstyled, ol.unnumbered, ul.checklist {
    margin-left: 0.625em;
}

ul.checklist li > p:first-child > i[class^="icon-check"]:first-child, ul.checklist li > p:first-child > input[type="checkbox"]:first-child {
    margin-right: 0.25em;
}

ul.checklist li > p:first-child > input[type="checkbox"]:first-child {
    position: relative;
    top: 1px;
}

ul.inline {
    margin: 0 auto 0.625em auto;
    margin-left: -1.375em;
    margin-right: 0;
    padding: 0;
    list-style: none;
    overflow: hidden;
}

ul.inline > li {
    list-style: none;
    float: left;
    margin-left: 1.375em;
    display: block;
}

ul.inline > li > * {
    display: block;
}

.unstyled dl dt {
    font-weight: normal;
    font-style: normal;
}

ol.arabic {
    list-style-type: decimal;
}

ol.decimal {
    list-style-type: decimal-leading-zero;
}

ol.loweralpha {
    list-style-type: lower-alpha;
}

ol.upperalpha {
    list-style-type: upper-alpha;
}

ol.lowerroman {
    list-style-type: lower-roman;
}

ol.upperroman {
    list-style-type: upper-roman;
}

ol.lowergreek {
    list-style-type: lower-greek;
}

.hdlist > table, .colist > table {
    border: 0;
    background: none;
}

.hdlist > table > tbody > tr, .colist > table > tbody > tr {
    background: none;
}

td.hdlist1 {
    padding-right: .8em;
    font-weight: bold;
}

td.hdlist1, td.hdlist2 {
    vertical-align: top;
}

.literalblock + .colist, .listingblock + .colist {
    margin-top: -0.5em;
}

.colist > table tr > td:first-of-type {
    padding: 0 .8em;
    line-height: 1;
}

.colist > table tr > td:last-of-type {
    padding: 0.25em 0;
}

.qanda > ol > li > p > em:only-child {
    color: var(--em-color);
}

.thumb, .th {
    line-height: 0;
    display: inline-block;
    border: solid 4px white;
    -webkit-box-shadow: 0 0 0 1px var(--border2);
    box-shadow: 0 0 0 1px var(--border2);
}

.imageblock.left, .imageblock[style*="float: left"] {
    margin: 0.25em 0.625em 1.25em 0;
}

.imageblock.right, .imageblock[style*="float: right"] {
    margin: 0.25em 0 1.25em 0.625em;
}

.imageblock > .title {
    margin-bottom: 0;
}

.imageblock.thumb, .imageblock.th {
    border-width: var(--border-radius-default);
}

.imageblock.thumb > .title, .imageblock.th > .title {
    padding: 0 0.125em;
}

.image.left, .image.right {
    margin-top: 0.25em;
    margin-bottom: 0.25em;
    display: inline-block;
    line-height: 0;
}

.image.left {
    margin-right: 0.625em;
}

.image.right {
    margin-left: 0.625em;
}

a.image {
    text-decoration: none;
}

span.footnote, span.footnoteref {
    vertical-align: super;
    font-size: 0.875em;
}

span.footnote a, span.footnoteref a {
    text-decoration: none;
}

#footnotes {
    padding-top: 0.75em;
    padding-bottom: 0.75em;
    margin-bottom: 0.625em;
}

#footnotes hr {
    width: 20%;
    min-width: 6.25em;
    margin: -.25em 0 .75em 0;
    border-width: 1px 0 0 0;
}

#footnotes .footnote {
    padding: 0 0.375em;
    line-height: 1.3;
    font-size: 0.875em;
    margin-left: 1.2em;
    text-indent: -1.2em;
    margin-bottom: .2em;
}

#footnotes .footnote a:first-of-type {
    font-weight: bold;
    text-decoration: none;
}

#footnotes .footnote:last-of-type {
    margin-bottom: 0;
}

#content #footnotes {
    margin-top: -0.625em;
    margin-bottom: 0;
    padding: 0.75em 0;
}

.gist .file-data > table {
    border: none;
    background: var(--background);
    width: 100%;
    margin-bottom: 0;
}

.gist .file-data > table td.line-data {
    width: 99%;
}

div.unbreakable {
    page-break-inside: avoid;
}

.big {
    font-size: larger;
}

.small {
    font-size: smaller;
}

.underline {
    text-decoration: underline;
}

.overline {
    text-decoration: overline;
}

.line-through {
    text-decoration: line-through;
}

.aqua {
    color: #00bfbf;
}

.aqua-background {
    background-color: #00fafa;
}

.black {
    color: black;
}

.black-background {
    background-color: black;
}

.blue {
    color: #0000bf;
}

.blue-background {
    background-color: #0000fa;
}

.fuchsia {
    color: #bf00bf;
}

.fuchsia-background {
    background-color: #fa00fa;
}

.gray {
    color: #606060;
}

.gray-background {
    background-color: #7d7d7d;
}

.green {
    color: #006000;
}

.green-background {
    background-color: #007d00;
}

.lime {
    color: #00bf00;
}

.lime-background {
    background-color: #00fa00;
}

.maroon {
    color: #600000;
}

.maroon-background {
    background-color: #7d0000;
}

.navy {
    color: #000060;
}

.navy-background {
    background-color: #00007d;
}

.olive {
    color: #606000;
}

.olive-background {
    background-color: #7d7d00;
}

.purple {
    color: #600060;
}

.purple-background {
    background-color: #7d007d;
}

.red {
    color: #bf0000;
}

.red-background {
    background-color: #fa0000;
}

.silver {
    color: #909090;
}

.silver-background {
    background-color: #bcbcbc;
}

.teal {
    color: #006060;
}

.teal-background {
    background-color: #007d7d;
}

.white {
    color: #bfbfbf;
}

.white-background {
    background-color: #fafafa;
}

.yellow {
    color: #bfbf00;
}

.yellow-background {
    background-color: #fafa00;
}

span.icon > [class^="icon-"], span.icon > [class*=" icon-"] {
    cursor: default;
}


.admonitionblock td.icon [class^="icon-"]:before {
    font-size: 2.5em;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.5);
    cursor: default;
}

.admonitionblock td.icon .icon-note:before {
    content: "\f05a";
    color: var(--accent-primary-color);
}

.admonitionblock td.icon .icon-tip:before {
    content: "\f0eb";
    /*text-shadow: 1px 1px 2px var(--accent-primary-color);*/
    color: var(--accent-primary-color);
}

.fa {
    font-family: "FontAwesome", "Helvetica Neue", sans-serif;
}

.admonitionblock td.icon .icon-warning:before {
    content: "\f071";
    color: #bf6900;
}

.admonitionblock td.icon .icon-caution:before {
    content: "\f06d";
    color: #bf3400;
}

.admonitionblock td.icon .icon-important:before {
    content: "\f06a";
    color: #bf0000;
}

.conum {
    display: inline-block;
    color: white !important;
    background-color: black;
    -webkit-border-radius: 100px;
    border-radius: 100px;
    text-align: center;
    width: 20px;
    height: 20px;
    font-size: 12px;
    font-weight: bold;
    line-height: 20px;
    font-family: Arial, sans-serif;
    font-style: normal;
    position: relative;
    top: -2px;
    letter-spacing: -1px;
}

.conum * {
    color: white !important;
}

.conum + b {
    display: none;
}

.conum:after {
    content: attr(data-value);
}

.conum:not([data-value]):empty {
    display: none;
}

h4 {
    color: var(--gray-color);
}

.literalblock > .content > pre, .listingblock > .content > pre {
    -webkit-border-radius: var(--border-radius-default);
    border-radius: var(--border-radius-default);
    margin-left: 0.5em;
    margin-right: 0.5em;
}

.admonitionblock {
    margin-left: .5em;
    margin-right: .5em;
}

.admonitionblock > table {
    border: 1px solid var(--accent-primary-color);
    border-left-width: 4px;
    background-color: var(--admotion-background-color);
    border-collapse: separate;
    -webkit-border-radius: var(--border-radius-default);
    border-radius: var(--border-radius-default);
}

.admonitionblock > table td.icon {
    padding-top: .5em;
    padding-bottom: .5em;
}

.admonitionblock > table td.content {
    padding: .5em .2em;
    color: black;
    font-size: .9em;
    border-left: none;
}

.sidebarblock {
    background-color: var(--sidebar-background-color);
    border-color: #ccc;
}

.sidebarblock > .content > .title {
    color: var(--link-color-default);
}

table.tableblock.grid-all {
    border-collapse: collapse;
    -webkit-border-radius: 0;
    border-radius: 0;
}

table.tableblock.grid-all th.tableblock, table.tableblock.grid-all td.tableblock {
    border-bottom: 1px solid #aaa;
}

#footer {
    background-color: var(--accent-primary-color);
    padding: 2em;
}

#footer-text {
    color: #eee;
    font-size: 0.8em;
    text-align: center;
}
</style>
<style>
pre.rouge table td { padding: 5px; }
pre.rouge table pre { margin: 0; }
pre.rouge, pre.rouge .w {
  color: #24292f;
  background-color: #f6f8fa;
}
pre.rouge .k, pre.rouge .kd, pre.rouge .kn, pre.rouge .kp, pre.rouge .kr, pre.rouge .kt, pre.rouge .kv {
  color: #cf222e;
}
pre.rouge .gr {
  color: #f6f8fa;
}
pre.rouge .gd {
  color: #82071e;
  background-color: #ffebe9;
}
pre.rouge .nb {
  color: #953800;
}
pre.rouge .nc {
  color: #953800;
}
pre.rouge .no {
  color: #953800;
}
pre.rouge .nn {
  color: #953800;
}
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<body class="article toc2 toc-left">
<div id="header">
<h1>Value conversion sample</h1>
<div id="toc" class="toc2">
<div id="toctitle">Table of Contents</div>
<ul class="sectlevel1">
<li><a href="#_before_we_start">Before we start</a>
<ul class="sectlevel2">
<li><a href="#_ivalueconverter">IValueConverter</a></li>
<li><a href="#_imultivalueconverter">IMultiValueConverter</a></li>
</ul>
</li>
<li><a href="#_the_solution_1_using_ivalueconverter">The Solution 1 : Using IValueConverter</a>
<ul class="sectlevel2">
<li><a href="#_step_1_setup_your_viewmodel">Step 1: Setup your ViewModel</a></li>
<li><a href="#_step_2_create_the_mathaddconverter">Step 2: Create the MathAddConverter</a></li>
<li><a href="#_step_3_setup_the_view">Step 3: Setup the View</a></li>
<li><a href="#_step_4_see_it_in_action">Step 4: See it in action</a></li>
</ul>
</li>
<li><a href="#_solution_2_using_imultivalueconverter">Solution 2 : Using IMultiValueConverter</a>
<ul class="sectlevel2">
<li><a href="#_step_1_setup_your_viewmodel_2">Step 1: Setup your ViewModel</a></li>
<li><a href="#_step_2_create_the_mathmulticonverter">Step 2: Create the MathMultiConverter</a></li>
<li><a href="#_step_3_setup_the_view_2">Step 3: Setup the View</a></li>
<li><a href="#_step_4_see_it_in_action_2">Step 4: See it in action</a></li>
</ul>
</li>
<li><a href="#_solution_3_using_funcvalueconverter">Solution 3 : Using FuncValueConverter</a>
<ul class="sectlevel2">
<li><a href="#_step_1_create_the_funcvalueconverters">Step 1 : Create the FuncValueConverters</a></li>
<li><a href="#_step_2_setup_the_view">Step 2: Setup the View</a></li>
<li><a href="#_step_3_see_it_in_action">Step 3: See it in action</a></li>
</ul>
</li>
<li><a href="#_related">Related</a></li>
</ul>
</div>
</div>
<div id="content">
<div id="preamble">
<div class="sectionbody">
<div class="paragraph">
<p>In this sample you will learn how you can use a <code>Converter</code> inside your <code>Binding</code> in order to calculate a new value for the <code>View</code>. This can be useful if you need to do some math operations or other conversions like showing different colors for different object states.</p>
</div>
<!-- toc disabled -->
<h3 id="_difficulty" class="discrete">Difficulty</h3>
<div class="paragraph">
<p>🐥 Easy 🐥</p>
</div>
<h3 id="_buzz_words" class="discrete">Buzz-Words</h3>
<div class="paragraph">
<p>Converter, Binding, MultiBinding, IValueConverter, IMultiValueConverter, MVVM, FuncValueConverter</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_before_we_start">Before we start</h2>
<div class="sectionbody">
<div class="paragraph">
<p>In this sample we assume that you know what a <code>Binding</code> is and that you have a basic knowledge of the <code>MVVM</code> concepts. Moreover you should already know how to create a new Avalonia project.</p>
</div>
<div class="paragraph">
<p>In case you want to refresh your knowledge, visit the <a href="../BasicMvvmSample">[Basic MVVM Sample]</a>.</p>
</div>
<div class="sect2">
<h3 id="_ivalueconverter">IValueConverter</h3>
<div class="paragraph">
<p>If your class implements <a href="http://reference.avaloniaui.net/api/Avalonia.Data.Converters/IValueConverter/">[<code>IValueConverter</code>]</a>, it can be used to convert a value provided by a <code>Binding</code> into any other <code>object</code>. The interface implements the following members:</p>
</div>
<div class="dlist">
<dl>
<dt class="hdlist1">Convert</dt>
<dd>
<p>This method will be called from your <code>Binding</code> when a new value is provided by the <code>Property</code> you bind to. For details about the parameters and return value, see the <a href="http://reference.avaloniaui.net/api/Avalonia.Data.Converters/IValueConverter/E7851E09">[API Reference]</a>.</p>
</dd>
<dt class="hdlist1">ConvertBack</dt>
<dd>
<p>This method will be called from your <code>Binding</code> when a new value is provided by the user interface and will set the bound <code>Property</code> in your <code>ViewModel</code>. For details about the parameters and return value, see the <a href="http://reference.avaloniaui.net/api/Avalonia.Data.Converters/IValueConverter/6880ABBD">[API Reference]</a>.</p>
</dd>
</dl>
</div>
<div class="admonitionblock warning">
<table>
<tr>
<td class="icon">
<i class="fa icon-warning" title="Warning"></i>
</td>
<td class="content">
You should not throw exceptions inside your converter. If the value is not convertible, return a <a href="http://reference.avaloniaui.net/api/Avalonia.Data/BindingNotification/">[<code>BindingNotification</code>]</a> in an error state or <a href="http://reference.avaloniaui.net/api/Avalonia.Data/BindingOperations/788823DA">[<code>BindingOperations.DoNothing</code>]</a> if your converter should just not do anything.
</td>
</tr>
</table>
</div>
<div class="admonitionblock tip">
<table>
<tr>
<td class="icon">
<i class="fa icon-tip" title="Tip"></i>
</td>
<td class="content">
If you don&#8217;t want to support <code>Convert</code> or <code>ConvertBack</code>, you can simply return <a href="http://reference.avaloniaui.net/api/Avalonia.Data/BindingOperations/788823DA">[<code>BindingOperations.DoNothing</code>]</a>. This will prevent the <code>Binding</code> from updating.
</td>
</tr>
</table>
</div>
</div>
<div class="sect2">
<h3 id="_imultivalueconverter">IMultiValueConverter</h3>
<div class="paragraph">
<p>If your class implements <a href="http://reference.avaloniaui.net/api/Avalonia.Data.Converters/IMultiValueConverter/">[<code>IMultiValueConverter</code>]</a>, it can be used to convert an array of values provided by a <code>MultiBinding</code> into any <code>object</code>. The interface implements the following member:</p>
</div>
<div class="dlist">
<dl>
<dt class="hdlist1">Convert</dt>
<dd>
<p>This method will be called from your <code>Binding</code> when a new value is provided by the <code>Property</code> you bind to. For details about the parameters and return value, see the <a href="http://reference.avaloniaui.net/api/Avalonia.Data.Converters/IMultiValueConverter/38695B84">[API Reference]</a>.</p>
</dd>
</dl>
</div>
<div class="admonitionblock warning">
<table>
<tr>
<td class="icon">
<i class="fa icon-warning" title="Warning"></i>
</td>
<td class="content">
You should not throw exceptions inside your converter. If the value is not convertible, return a <a href="http://reference.avaloniaui.net/api/Avalonia.Data/BindingNotification/">[<code>BindingNotification</code>]</a> in an error state or <a href="http://reference.avaloniaui.net/api/Avalonia.Data/BindingOperations/788823DA">[<code>BindingOperations.DoNothing</code>]</a> if your converter should just not do anything.
</td>
</tr>
</table>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
Other than in <code>IValueConverter</code> the method <code>ConvertBack</code> is not present for <code>IMultiValueConverter</code>.
</td>
</tr>
</table>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_the_solution_1_using_ivalueconverter">The Solution 1 : Using IValueConverter</h2>
<div class="sectionbody">
<div class="paragraph">
<p>In this sample we will write a <code>Converter</code> that can be used to add a constant number to another number. The number to add will be provided by the <code>ConverterParameter</code>. In the <code>ConvertBack</code> method we will subtract the parameter.</p>
</div>
<div class="sect2">
<h3 id="_step_1_setup_your_viewmodel">Step 1: Setup your ViewModel</h3>
<div class="paragraph">
<p>In your <code>MainWindowViewModel</code> add a <code>decimal</code> called <code>Number1</code> like shown below:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="cs"><span class="c1">// The initial value is 2.</span>
<span class="k">private</span> <span class="kt">decimal</span><span class="p">?</span> <span class="n">_Number1</span> <span class="p">=</span> <span class="m">2</span><span class="p">;</span>

<span class="c1">/// &lt;summary&gt;</span>
<span class="c1">/// This is our Number 1</span>
<span class="c1">/// &lt;/summary&gt;</span>
<span class="k">public</span> <span class="kt">decimal</span><span class="p">?</span> <span class="n">Number1</span>
<span class="p">{</span>
    <span class="k">get</span> <span class="p">{</span> <span class="k">return</span> <span class="n">_Number1</span><span class="p">;</span> <span class="p">}</span>
    <span class="k">set</span> <span class="p">{</span> <span class="k">this</span><span class="p">.</span><span class="nf">RaiseAndSetIfChanged</span><span class="p">(</span><span class="k">ref</span> <span class="n">_Number1</span><span class="p">,</span> <span class="k">value</span><span class="p">);</span> <span class="p">}</span>
<span class="p">}</span></code></pre>
</div>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
The <code>NumericUpDown</code> control works best with <code>decimal</code> or <code>decimal</code> values as these can store exact numbers. <a href="https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/floating-podecimal-numeric-types">[more about it]</a>
</td>
</tr>
</table>
</div>
</div>
<div class="sect2">
<h3 id="_step_2_create_the_mathaddconverter">Step 2: Create the MathAddConverter</h3>
<div class="paragraph">
<p>In the project we create a new folder called <code>Converter</code>. This will be the place where we keep all our converters. Inside this folder we add a <code>class</code> called <code>MathAddConverter.cs</code>. This <code>class</code> should implement <code>IValueConverter</code>.</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="cs"><span class="k">using</span> <span class="nn">Avalonia.Data.Converters</span><span class="p">;</span>
<span class="k">using</span> <span class="nn">System</span><span class="p">;</span>
<span class="k">using</span> <span class="nn">System.Globalization</span><span class="p">;</span>

<span class="k">namespace</span> <span class="nn">ValueConversionSample.Converter</span>
<span class="p">{</span>
    <span class="c1">/// &lt;summary&gt;</span>
    <span class="c1">/// This is a converter which will add two numbers</span>
    <span class="c1">/// &lt;/summary&gt;</span>
    <span class="k">public</span> <span class="k">class</span> <span class="nc">MathAddConverter</span> <span class="p">:</span> <span class="n">IValueConverter</span>
    <span class="p">{</span>
        <span class="k">public</span> <span class="kt">object</span><span class="p">?</span> <span class="nf">Convert</span><span class="p">(</span><span class="kt">object</span><span class="p">?</span> <span class="k">value</span><span class="p">,</span> <span class="n">Type</span> <span class="n">targetType</span><span class="p">,</span> <span class="kt">object</span><span class="p">?</span> <span class="n">parameter</span><span class="p">,</span> <span class="n">CultureInfo</span> <span class="n">culture</span><span class="p">)</span>
        <span class="p">{</span>
            <span class="c1">// For add this is simple. just return the sum of the value and the parameter.</span>
            <span class="c1">// You may want to validate value and parameter in a real world App</span>
            <span class="k">return</span> <span class="p">(</span><span class="kt">decimal</span><span class="p">?)</span><span class="k">value</span> <span class="p">+</span> <span class="p">(</span><span class="kt">decimal</span><span class="p">?)</span><span class="n">parameter</span><span class="p">;</span>
        <span class="p">}</span>

        <span class="k">public</span> <span class="kt">object</span><span class="p">?</span> <span class="nf">ConvertBack</span><span class="p">(</span><span class="kt">object</span><span class="p">?</span> <span class="k">value</span><span class="p">,</span> <span class="n">Type</span> <span class="n">targetType</span><span class="p">,</span> <span class="kt">object</span><span class="p">?</span> <span class="n">parameter</span><span class="p">,</span> <span class="n">CultureInfo</span> <span class="n">culture</span><span class="p">)</span>
        <span class="p">{</span>
            <span class="c1">// If we want to convert back, we need to subtract instead of add.</span>
            <span class="k">return</span> <span class="p">(</span><span class="kt">decimal</span><span class="p">?)</span><span class="k">value</span> <span class="p">-</span> <span class="p">(</span><span class="kt">decimal</span><span class="p">?)</span><span class="n">parameter</span><span class="p">;</span>
        <span class="p">}</span>
    <span class="p">}</span>
<span class="p">}</span></code></pre>
</div>
</div>
<div class="paragraph">
<p>To clarify things further:</p>
</div>
<div class="dlist">
<dl>
<dt class="hdlist1">value</dt>
<dd>
<p>This is the value which is provided by the <code>Binding</code>.</p>
</dd>
<dt class="hdlist1">parameter</dt>
<dd>
<p>This is an optional converter parameter. We will see later how we can provide this parameter.</p>
</dd>
</dl>
</div>
</div>
<div class="sect2">
<h3 id="_step_3_setup_the_view">Step 3: Setup the View</h3>
<div class="paragraph">
<p>First we need to create a new instance of our <code>MathAddConverter</code> and the <code>ConverterParameter</code> as a <a href="https://docs.avaloniaui.net/docs/styling/resources">[<code>Resource</code>]</a> which can be used later. We do this inside <code>Window.Resources</code>, but it can be done also in <code>App.axaml</code> or in any other <code>Resources</code>-section.</p>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
Each Resource must have a unique key defined by <code>x:Key</code>
</td>
</tr>
</table>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="xml"><span class="nt">&lt;Window</span> <span class="na">x:Class=</span><span class="s">"ValueConversionSample.Views.MainWindow"</span>
        <span class="na">xmlns=</span><span class="s">"https://github.com/avaloniaui"</span>
        <span class="na">xmlns:x=</span><span class="s">"http://schemas.microsoft.com/winfx/2006/xaml"</span>
        <span class="na">xmlns:conv=</span><span class="s">"using:ValueConversionSample.Converter"</span>
        <span class="na">xmlns:d=</span><span class="s">"http://schemas.microsoft.com/expression/blend/2008"</span>
        <span class="na">xmlns:mc=</span><span class="s">"http://schemas.openxmlformats.org/markup-compatibility/2006"</span>
        <span class="na">xmlns:vm=</span><span class="s">"using:ValueConversionSample.ViewModels"</span>
        <span class="na">Title=</span><span class="s">"ValueConversionSample"</span>
        <span class="na">Width=</span><span class="s">"500"</span> <span class="na">Height=</span><span class="s">"200"</span>
        <span class="na">x:CompileBindings=</span><span class="s">"True"</span> <span class="na">x:DataType=</span><span class="s">"vm:MainWindowViewModel"</span>
        <span class="na">Icon=</span><span class="s">"/Assets/avalonia-logo.ico"</span>
        <span class="na">mc:Ignorable=</span><span class="s">"d"</span><span class="nt">&gt;</span>
    <span class="nt">&lt;Window.Resources&gt;</span>
        <span class="c">&lt;!--  Add the MathAddConverter. Remember to add the needed namespace "conv" --&gt;</span>
        <span class="nt">&lt;conv:MathAddConverter</span> <span class="na">x:Key=</span><span class="s">"MathAddConverter"</span> <span class="nt">/&gt;</span>
        <span class="c">&lt;!--  This Resource will be used as our ConverterParameter  --&gt;</span>
        <span class="nt">&lt;x:Decimal</span> <span class="na">x:Key=</span><span class="s">"MyConverterParameter"</span><span class="nt">&gt;</span>2<span class="nt">&lt;/x:Decimal&gt;</span>
    <span class="nt">&lt;/Window.Resources&gt;</span>
<span class="nt">&lt;/Window&gt;</span></code></pre>
</div>
</div>
<div class="paragraph">
<p>Now we can add two <a href="https://docs.avaloniaui.net/docs/controls/numericupdown">[<code>NumericUpDown</code>]</a>-controls to our UI. Both will bind to <code>Number1</code> while the second one will use our <code>Converter</code> to calculate the sum of <code>Number1</code> and the <code>ConverterParameter</code> defined in <code>Resources</code>.</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="xml"><span class="nt">&lt;Grid</span> <span class="na">ColumnDefinitions=</span><span class="s">"Auto, *"</span> <span class="na">RowDefinitions=</span><span class="s">"Auto, Auto"</span><span class="nt">&gt;</span>
    <span class="nt">&lt;TextBlock</span> <span class="na">Grid.Row=</span><span class="s">"0"</span> <span class="na">Grid.Column=</span><span class="s">"0"</span>
               <span class="na">Text=</span><span class="s">"Number 1"</span> <span class="nt">/&gt;</span>
    <span class="nt">&lt;NumericUpDown</span> <span class="na">Grid.Row=</span><span class="s">"0"</span> <span class="na">Grid.Column=</span><span class="s">"1"</span>
                   <span class="na">Value=</span><span class="s">"{Binding Number1}"</span> <span class="nt">/&gt;</span>

    <span class="nt">&lt;TextBlock</span> <span class="na">Grid.Row=</span><span class="s">"1"</span> <span class="na">Grid.Column=</span><span class="s">"0"</span>
                <span class="na">Text=</span><span class="s">"Sum"</span> <span class="nt">/&gt;</span>
    <span class="nt">&lt;NumericUpDown</span> <span class="na">Grid.Row=</span><span class="s">"1"</span> <span class="na">Grid.Column=</span><span class="s">"1"</span>
                   <span class="na">Value=</span><span class="s">"{Binding Number1, Converter={StaticResource MathAddConverter}, ConverterParameter={StaticResource MyConverterParameter}}"</span> <span class="nt">/&gt;</span>
<span class="nt">&lt;/Grid&gt;</span></code></pre>
</div>
</div>
<div class="admonitionblock tip">
<table>
<tr>
<td class="icon">
<i class="fa icon-tip" title="Tip"></i>
</td>
<td class="content">
<code>ConverterParameter</code> can only be a static value. You cannot bind to it and you cannot use <code>DynamicResource</code>. If you need more flexibility, consider to do your calculations in your <code>ViewModel</code> or use a <code>MultiValueConverter</code>.
</td>
</tr>
</table>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
<div class="paragraph">
<p>If you want to, you can also define the converter as a static member and use it without the need to add it to the <code>Resources</code></p>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="cs"><span class="c1">/// &lt;summary&gt;</span>
<span class="c1">/// Gets a static instance of the MathAddConverter</span>
<span class="c1">/// &lt;/summary&gt;</span>
<span class="k">public</span> <span class="k">static</span> <span class="n">MathAddConverter</span> <span class="n">AddConverter</span> <span class="p">{</span> <span class="k">get</span><span class="p">;</span> <span class="p">}</span> <span class="p">=</span> <span class="k">new</span> <span class="nf">MathAddConverter</span><span class="p">();</span></code></pre>
</div>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="xml"><span class="nt">&lt;NumericUpDown</span> <span class="na">Grid.Row=</span><span class="s">"1"</span> <span class="na">Grid.Column=</span><span class="s">"1"</span>
               <span class="na">Value=</span><span class="s">"{Binding Number1, Converter={x:Static MathAddConverter.AddConverter}, ConverterParameter={StaticResource MyConverterParameter}}"</span> <span class="nt">/&gt;</span></code></pre>
</div>
</div>
</td>
</tr>
</table>
</div>
</div>
<div class="sect2">
<h3 id="_step_4_see_it_in_action">Step 4: See it in action</h3>
<div class="paragraph">
<p>In your IDE select <code>[Run]</code> or <code>[Debug]</code> to see the result in action. Try to change the value in both input boxes and see how they update each other.</p>
</div>
<div class="imageblock">
<div class="content">
<img src="_docs/result_01.png" alt="IValueConverter sample">
</div>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_solution_2_using_imultivalueconverter">Solution 2 : Using IMultiValueConverter</h2>
<div class="sectionbody">
<div class="paragraph">
<p>If you want to bind to more than one value in your <code>Converter</code>, you can implement the interface <code>IMultiValueConverter</code>. In this sample we will take two numbers and calculate the result using a given operator. Because we want all three parameters to be dynamic, we will not use the <code>ConverterParameter</code> here.</p>
</div>
<div class="sect2">
<h3 id="_step_1_setup_your_viewmodel_2">Step 1: Setup your ViewModel</h3>
<div class="paragraph">
<p>In addition to our <code>Number1</code> from the above sample we will add another <code>decimal</code> called <code>Number2</code>, the <code>Operator</code> as <code>string</code> and a list of available <code>Operators</code> the user can choose from.</p>
</div>
<div class="admonitionblock tip">
<table>
<tr>
<td class="icon">
<i class="fa icon-tip" title="Tip"></i>
</td>
<td class="content">
The <code>Operator</code> is defined as <code>string</code> in our case, but it can also be a <code>char</code>, an <code>enum</code> or any other <code>object</code>.
</td>
</tr>
</table>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="cs"><span class="k">public</span> <span class="k">class</span> <span class="nc">MainWindowViewModel</span> <span class="p">:</span> <span class="n">ViewModelBase</span>
<span class="p">{</span>
    <span class="c1">// The initial value is 2.</span>
    <span class="k">private</span> <span class="kt">decimal</span><span class="p">?</span> <span class="n">_Number1</span> <span class="p">=</span> <span class="m">2</span><span class="p">;</span>

    <span class="c1">/// &lt;summary&gt;</span>
    <span class="c1">/// This is our Number 1</span>
    <span class="c1">/// &lt;/summary&gt;</span>
    <span class="k">public</span> <span class="kt">decimal</span><span class="p">?</span> <span class="n">Number1</span>
    <span class="p">{</span>
        <span class="k">get</span> <span class="p">{</span> <span class="k">return</span> <span class="n">_Number1</span><span class="p">;</span> <span class="p">}</span>
        <span class="k">set</span> <span class="p">{</span> <span class="k">this</span><span class="p">.</span><span class="nf">RaiseAndSetIfChanged</span><span class="p">(</span><span class="k">ref</span> <span class="n">_Number1</span><span class="p">,</span> <span class="k">value</span><span class="p">);</span> <span class="p">}</span>
    <span class="p">}</span>


    <span class="c1">// The initial value is 3.</span>
    <span class="k">private</span> <span class="kt">decimal</span><span class="p">?</span> <span class="n">_Number2</span> <span class="p">=</span> <span class="m">3</span><span class="p">;</span>

    <span class="c1">/// &lt;summary&gt;</span>
    <span class="c1">/// This is our Number 2</span>
    <span class="c1">/// &lt;/summary&gt;</span>
    <span class="k">public</span> <span class="kt">decimal</span><span class="p">?</span> <span class="n">Number2</span>
    <span class="p">{</span>
        <span class="k">get</span> <span class="p">{</span> <span class="k">return</span> <span class="n">_Number2</span><span class="p">;</span> <span class="p">}</span>
        <span class="k">set</span> <span class="p">{</span> <span class="k">this</span><span class="p">.</span><span class="nf">RaiseAndSetIfChanged</span><span class="p">(</span><span class="k">ref</span> <span class="n">_Number2</span><span class="p">,</span> <span class="k">value</span><span class="p">);</span> <span class="p">}</span>
    <span class="p">}</span>


    <span class="c1">// The initial value is "+" (Add).</span>
    <span class="k">private</span> <span class="kt">string</span> <span class="n">_Operator</span> <span class="p">=</span> <span class="s">"+"</span><span class="p">;</span>

    <span class="c1">/// &lt;summary&gt;</span>
    <span class="c1">/// Gets or sets the operator to use.</span>
    <span class="c1">/// &lt;/summary&gt;</span>
    <span class="k">public</span> <span class="kt">string</span> <span class="n">Operator</span>
    <span class="p">{</span>
        <span class="k">get</span> <span class="p">{</span> <span class="k">return</span> <span class="n">_Operator</span><span class="p">;</span> <span class="p">}</span>
        <span class="k">set</span> <span class="p">{</span> <span class="k">this</span><span class="p">.</span><span class="nf">RaiseAndSetIfChanged</span><span class="p">(</span><span class="k">ref</span> <span class="n">_Operator</span><span class="p">,</span> <span class="k">value</span><span class="p">);</span> <span class="p">}</span>
    <span class="p">}</span>

    <span class="c1">/// &lt;summary&gt;</span>
    <span class="c1">/// Gets a collection of available operators</span>
    <span class="c1">/// &lt;/summary&gt;</span>
    <span class="k">public</span> <span class="kt">string</span><span class="p">[]</span> <span class="n">AvailableMathOperators</span> <span class="p">{</span> <span class="k">get</span><span class="p">;</span> <span class="p">}</span> <span class="p">=</span> <span class="k">new</span> <span class="kt">string</span><span class="p">[]</span>
    <span class="p">{</span>
        <span class="s">"+"</span><span class="p">,</span> <span class="s">"-"</span><span class="p">,</span> <span class="s">"*"</span><span class="p">,</span> <span class="s">"/"</span>
    <span class="p">};</span>
<span class="p">}</span></code></pre>
</div>
</div>
</div>
<div class="sect2">
<h3 id="_step_2_create_the_mathmulticonverter">Step 2: Create the MathMultiConverter</h3>
<div class="paragraph">
<p>In the folder <code>Converter</code> add a new class called <code>MathMultiConverter.cs</code>, which implements <code>IMultiValueConverter</code> like shown below:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="cs"><span class="k">using</span> <span class="nn">Avalonia.Data</span><span class="p">;</span>
<span class="k">using</span> <span class="nn">Avalonia.Data.Converters</span><span class="p">;</span>
<span class="k">using</span> <span class="nn">System</span><span class="p">;</span>
<span class="k">using</span> <span class="nn">System.Collections.Generic</span><span class="p">;</span>
<span class="k">using</span> <span class="nn">System.Diagnostics</span><span class="p">;</span>
<span class="k">using</span> <span class="nn">System.Globalization</span><span class="p">;</span>

<span class="k">namespace</span> <span class="nn">ValueConversionSample.Converter</span>
<span class="p">{</span>
    <span class="c1">/// &lt;summary&gt;</span>
    <span class="c1">/// This converter can calculate any number of values.</span>
    <span class="c1">/// &lt;/summary&gt;</span>
    <span class="k">public</span> <span class="k">class</span> <span class="nc">MathMultiConverter</span> <span class="p">:</span> <span class="n">IMultiValueConverter</span>
    <span class="p">{</span>
        <span class="k">public</span> <span class="kt">object</span><span class="p">?</span> <span class="nf">Convert</span><span class="p">(</span><span class="n">IList</span><span class="p">&lt;</span><span class="kt">object</span><span class="p">?&gt;</span> <span class="n">values</span><span class="p">,</span> <span class="n">Type</span> <span class="n">targetType</span><span class="p">,</span> <span class="kt">object</span><span class="p">?</span> <span class="n">parameter</span><span class="p">,</span> <span class="n">CultureInfo</span> <span class="n">culture</span><span class="p">)</span>
        <span class="p">{</span>
            <span class="c1">// We need to validate if the provided values are valid. We need at least 3 values.</span>
            <span class="c1">// The first value is the operator and the other two values should be a decimal.</span>
            <span class="k">if</span> <span class="p">(</span><span class="n">values</span><span class="p">.</span><span class="n">Count</span> <span class="p">!=</span> <span class="m">3</span><span class="p">)</span>
            <span class="p">{</span>
                <span class="c1">// We can write a message into the Trace if we want to inform the developer.</span>
                <span class="n">Trace</span><span class="p">.</span><span class="nf">WriteLine</span><span class="p">(</span><span class="s">"Exactly three values expected"</span><span class="p">);</span>

                <span class="c1">// return "BindingOperations.DoNothing" instead of throwing an Exception.</span>
                <span class="c1">// If you want, you can also return a BindingNotification with an Exception</span>
                <span class="k">return</span> <span class="n">BindingOperations</span><span class="p">.</span><span class="n">DoNothing</span><span class="p">;</span>
            <span class="p">}</span>

            <span class="c1">// The first item of values is the operation.</span>
            <span class="c1">// The operation to use is stored as a string.</span>
            <span class="kt">string</span> <span class="n">operation</span> <span class="p">=</span> <span class="n">values</span><span class="p">[</span><span class="m">0</span><span class="p">]</span> <span class="k">as</span> <span class="kt">string</span> <span class="p">??</span> <span class="s">"+"</span><span class="p">;</span>

            <span class="c1">// Create a variable result and assign the first value we have to if</span>
            <span class="kt">decimal</span> <span class="n">value1</span> <span class="p">=</span> <span class="n">values</span><span class="p">[</span><span class="m">1</span><span class="p">]</span> <span class="k">as</span> <span class="kt">decimal</span><span class="p">?</span> <span class="p">??</span> <span class="m">0</span><span class="p">;</span>
            <span class="kt">decimal</span> <span class="n">value2</span> <span class="p">=</span> <span class="n">values</span><span class="p">[</span><span class="m">2</span><span class="p">]</span> <span class="k">as</span> <span class="kt">decimal</span><span class="p">?</span> <span class="p">??</span> <span class="m">0</span><span class="p">;</span>


            <span class="c1">// depending on the operator calculate the result.</span>
            <span class="k">switch</span> <span class="p">(</span><span class="n">operation</span><span class="p">)</span>
            <span class="p">{</span>
                <span class="k">case</span> <span class="s">"+"</span><span class="p">:</span>
                    <span class="k">return</span> <span class="n">value1</span> <span class="p">+</span> <span class="n">value2</span><span class="p">;</span>

                <span class="k">case</span> <span class="s">"-"</span><span class="p">:</span>
                    <span class="k">return</span> <span class="n">value1</span> <span class="p">-</span> <span class="n">value2</span><span class="p">;</span>

                <span class="k">case</span> <span class="s">"*"</span><span class="p">:</span>
                    <span class="k">return</span> <span class="n">value1</span> <span class="p">*</span> <span class="n">value2</span><span class="p">;</span>

                <span class="k">case</span> <span class="s">"/"</span><span class="p">:</span>
                    <span class="c1">// We cannot divide by zero. If value2 is '0', return an error.</span>
                    <span class="k">if</span> <span class="p">(</span><span class="n">value2</span> <span class="p">==</span> <span class="m">0</span><span class="p">)</span>
                    <span class="p">{</span>
                        <span class="k">return</span> <span class="k">new</span> <span class="nf">BindingNotification</span><span class="p">(</span><span class="k">new</span> <span class="nf">DivideByZeroException</span><span class="p">(</span><span class="s">"Don't do this!"</span><span class="p">),</span> <span class="n">BindingErrorType</span><span class="p">.</span><span class="n">Error</span><span class="p">);</span>
                    <span class="p">}</span>

                    <span class="k">return</span> <span class="n">value1</span> <span class="p">/</span> <span class="n">value2</span><span class="p">;</span>
            <span class="p">}</span>

            <span class="c1">// If we reach this line, something was wrong. So we return an error notification</span>
            <span class="k">return</span> <span class="k">new</span> <span class="nf">BindingNotification</span><span class="p">(</span><span class="k">new</span> <span class="nf">InvalidOperationException</span><span class="p">(</span><span class="s">"Something went wrong"</span><span class="p">),</span> <span class="n">BindingErrorType</span><span class="p">.</span><span class="n">Error</span><span class="p">);</span>
        <span class="p">}</span>
    <span class="p">}</span>
<span class="p">}</span></code></pre>
</div>
</div>
<div class="admonitionblock important">
<table>
<tr>
<td class="icon">
<i class="fa icon-important" title="Important"></i>
</td>
<td class="content">
The order of the <code>values</code> provided may be important like shown in our sample.
</td>
</tr>
</table>
</div>
<div class="admonitionblock tip">
<table>
<tr>
<td class="icon">
<i class="fa icon-tip" title="Tip"></i>
</td>
<td class="content">
The <code>??</code> in <code>C#</code> can be used to define a default value, if the value provided is <code>null</code>. See <a href="https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/null-coalescing-operator">[Microsoft Docs]</a>
</td>
</tr>
</table>
</div>
</div>
<div class="sect2">
<h3 id="_step_3_setup_the_view_2">Step 3: Setup the View</h3>
<div class="paragraph">
<p>Again we need to add a new <code>MathMultiConverter</code> into our <code>Resources</code> section:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="xml"><span class="nt">&lt;Window</span> <span class="na">x:Class=</span><span class="s">"ValueConversionSample.Views.MainWindow"</span>
        <span class="na">xmlns=</span><span class="s">"https://github.com/avaloniaui"</span> <span class="na">xmlns:x=</span><span class="s">"http://schemas.microsoft.com/winfx/2006/xaml"</span>
        <span class="na">xmlns:conv=</span><span class="s">"using:ValueConversionSample.Converter"</span> <span class="na">xmlns:d=</span><span class="s">"http://schemas.microsoft.com/expression/blend/2008"</span>
        <span class="na">xmlns:mc=</span><span class="s">"http://schemas.openxmlformats.org/markup-compatibility/2006"</span> <span class="na">xmlns:vm=</span><span class="s">"using:ValueConversionSample.ViewModels"</span>
        <span class="na">Title=</span><span class="s">"ValueConversionSample"</span>
        <span class="na">Width=</span><span class="s">"500"</span> <span class="na">Height=</span><span class="s">"200"</span>
        <span class="na">x:CompileBindings=</span><span class="s">"True"</span> <span class="na">x:DataType=</span><span class="s">"vm:MainWindowViewModel"</span>
        <span class="na">Icon=</span><span class="s">"/Assets/avalonia-logo.ico"</span>
        <span class="na">mc:Ignorable=</span><span class="s">"d"</span><span class="nt">&gt;</span>

    <span class="nt">&lt;Window.Resources&gt;</span>
        <span class="c">&lt;!--  Add the MathMultiConverter  --&gt;</span>
        <span class="nt">&lt;conv:MathMultiConverter</span> <span class="na">x:Key=</span><span class="s">"MathMultiConverter"</span> <span class="nt">/&gt;</span>
    <span class="nt">&lt;/Window.Resources&gt;</span>
<span class="nt">&lt;/Window&gt;</span></code></pre>
</div>
</div>
<div class="paragraph">
<p>Our view will consist of one <a href="https://docs.avaloniaui.net/docs/controls/combobox">[<code>ComboBox</code>]</a> and two <code>NumericUpDown</code>-controls. In the <code>ComboBox</code> the user can select one of the available operators.</p>
</div>
<div class="paragraph">
<p>The result will be shown in another <code>NumericUpDown</code>-control, which is read-only. As we cannot convert back, a user input is not allowed here. As you can see we use a <code>MultiBinding</code> with three nested <code>Bindings</code>:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="xml"><span class="nt">&lt;Grid</span> <span class="na">ColumnDefinitions=</span><span class="s">"Auto, *"</span> <span class="na">RowDefinitions=</span><span class="s">"Auto, Auto, Auto, Auto"</span><span class="nt">&gt;</span>

    <span class="nt">&lt;TextBlock</span> <span class="na">Grid.Row=</span><span class="s">"0"</span> <span class="na">Grid.Column=</span><span class="s">"0"</span>
                <span class="na">Text=</span><span class="s">"Operator"</span> <span class="nt">/&gt;</span>
    <span class="nt">&lt;ComboBox</span> <span class="na">Grid.Row=</span><span class="s">"0"</span> <span class="na">Grid.Column=</span><span class="s">"1"</span>
                <span class="na">ItemsSource=</span><span class="s">"{Binding AvailableMathOperators}"</span>
                <span class="na">SelectedItem=</span><span class="s">"{Binding Operator}"</span> <span class="nt">/&gt;</span>

    <span class="nt">&lt;TextBlock</span> <span class="na">Grid.Row=</span><span class="s">"1"</span> <span class="na">Grid.Column=</span><span class="s">"0"</span>
                <span class="na">Text=</span><span class="s">"Number 1"</span> <span class="nt">/&gt;</span>
    <span class="nt">&lt;NumericUpDown</span> <span class="na">Grid.Row=</span><span class="s">"1"</span> <span class="na">Grid.Column=</span><span class="s">"1"</span>
                    <span class="na">Value=</span><span class="s">"{Binding Number1}"</span> <span class="nt">/&gt;</span>

    <span class="nt">&lt;TextBlock</span> <span class="na">Grid.Row=</span><span class="s">"2"</span> <span class="na">Grid.Column=</span><span class="s">"0"</span>
                <span class="na">Text=</span><span class="s">"Number 2"</span> <span class="nt">/&gt;</span>
    <span class="nt">&lt;NumericUpDown</span> <span class="na">Grid.Row=</span><span class="s">"2"</span> <span class="na">Grid.Column=</span><span class="s">"1"</span>
                    <span class="na">Value=</span><span class="s">"{Binding Number2}"</span> <span class="nt">/&gt;</span>

    <span class="nt">&lt;TextBlock</span> <span class="na">Grid.Row=</span><span class="s">"3"</span> <span class="na">Grid.Column=</span><span class="s">"0"</span>
                <span class="na">Text=</span><span class="s">"Result"</span> <span class="nt">/&gt;</span>
    <span class="nt">&lt;NumericUpDown</span> <span class="na">Grid.Row=</span><span class="s">"3"</span> <span class="na">Grid.Column=</span><span class="s">"1"</span>
                    <span class="na">IsReadOnly=</span><span class="s">"True"</span><span class="nt">&gt;</span>
        <span class="nt">&lt;NumericUpDown.Value&gt;</span>
            <span class="nt">&lt;MultiBinding</span> <span class="na">Converter=</span><span class="s">"{StaticResource MathMultiConverter}"</span> <span class="na">Mode=</span><span class="s">"OneWay"</span><span class="nt">&gt;</span>
                <span class="nt">&lt;Binding</span> <span class="na">Path=</span><span class="s">"Operator"</span> <span class="nt">/&gt;</span>
                <span class="nt">&lt;Binding</span> <span class="na">Path=</span><span class="s">"Number1"</span> <span class="nt">/&gt;</span>
                <span class="nt">&lt;Binding</span> <span class="na">Path=</span><span class="s">"Number2"</span> <span class="nt">/&gt;</span>
            <span class="nt">&lt;/MultiBinding&gt;</span>
        <span class="nt">&lt;/NumericUpDown.Value&gt;</span>
    <span class="nt">&lt;/NumericUpDown&gt;</span>
<span class="nt">&lt;/Grid&gt;</span></code></pre>
</div>
</div>
<div class="admonitionblock warning">
<table>
<tr>
<td class="icon">
<i class="fa icon-warning" title="Warning"></i>
</td>
<td class="content">
Input-controls have <code>Properties</code> that binds <code>TwoWay</code> by default, like <code>TextBox.Text</code> or <code>NumericUpDown.Value</code>. If you require a <code>OneWay-Binding</code>, you must set the <a href="https://docs.avaloniaui.net/docs/data-binding/bindings#binding-modes">[<code>BindingMode</code>]</a> to <code>OneWay</code> on your own. Otherwise your App will fail when trying to update the <code>Binding</code>.
</td>
</tr>
</table>
</div>
</div>
<div class="sect2">
<h3 id="_step_4_see_it_in_action_2">Step 4: See it in action</h3>
<div class="paragraph">
<p>In your IDE select <code>[Run]</code> or <code>[Debug]</code> to see the result in action. Try to change the value in both input boxes and the <code>ComboBox</code> and see how they update the result.</p>
</div>
<div class="imageblock">
<div class="content">
<img src="_docs/result_02.png" alt="IMultiValueConverter sample">
</div>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_solution_3_using_funcvalueconverter">Solution 3 : Using FuncValueConverter</h2>
<div class="sectionbody">
<div class="paragraph">
<p>In case you need a converter that only converts a given input in one direction without the need of a <code>ConverterParameter</code>, you can also use a <code>FuncValueConverter</code>. The benefit is, that the converter is much shorter to write. In this sample we will add a <code>FuncValueConverter</code> which will try to parse a given text into a brush representing the color name. It will return <code>null</code>, if conversion failed. We will consume the converter to preview the color, that the user typed.</p>
</div>
<div class="sect2">
<h3 id="_step_1_create_the_funcvalueconverters">Step 1 : Create the FuncValueConverters</h3>
<div class="admonitionblock tip">
<table>
<tr>
<td class="icon">
<i class="fa icon-tip" title="Tip"></i>
</td>
<td class="content">
We can use a static class with static properties here as the converters will not change.
</td>
</tr>
</table>
</div>
<div class="paragraph">
<p>The <code>FuncValueConverter</code> has two generic parameters:</p>
</div>
<div class="dlist">
<dl>
<dt class="hdlist1">TIn</dt>
<dd>
<p>This parameter defines the expected input type. This can also be an array in case you want to use this converter in a <code>MultiBinding</code>.</p>
</dd>
<dt class="hdlist1">TOut</dt>
<dd>
<p>This parameter defines the expected output type.</p>
</dd>
</dl>
</div>
<div class="paragraph">
<p>The constructor expects a lambda defining the function to convert.</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="c#"><span class="c1">/// &lt;summary&gt;</span>
<span class="c1">/// A static class holding our FuncValueConverter</span>
<span class="c1">/// &lt;/summary&gt;</span>
<span class="c1">/// &lt;remarks&gt;</span>
<span class="c1">/// Consume it from XAML via &lt;code&gt;{x:Static conv:FuncValueConverters.MyConverter}&lt;/code&gt;</span>
<span class="c1">/// &lt;/remarks&gt;</span>
<span class="k">public</span> <span class="k">static</span> <span class="k">class</span> <span class="nc">FuncValueConverters</span>
<span class="p">{</span>
    <span class="c1">/// &lt;summary&gt;</span>
    <span class="c1">/// Gets a Converter that returns a parsed Brush for a given input. Returns null if the input was not parsed successfully</span>
    <span class="c1">/// &lt;/summary&gt;</span>
    <span class="k">public</span> <span class="k">static</span> <span class="n">FuncValueConverter</span><span class="p">&lt;</span><span class="kt">string</span><span class="p">?,</span> <span class="n">Brush</span><span class="p">?&gt;</span> <span class="n">StringToBrushConverter</span> <span class="p">{</span> <span class="k">get</span><span class="p">;</span> <span class="p">}</span> <span class="p">=</span>
        <span class="k">new</span> <span class="n">FuncValueConverter</span><span class="p">&lt;</span><span class="kt">string</span><span class="p">?,</span> <span class="n">Brush</span><span class="p">?&gt;(</span><span class="n">s</span> <span class="p">=&gt;</span>
        <span class="p">{</span>
            <span class="c1">// define output variable</span>
            <span class="n">Color</span> <span class="n">color</span><span class="p">;</span>

            <span class="c1">// try parse color. If that was not successful try to add a leading '#'</span>
            <span class="k">if</span> <span class="p">(</span><span class="n">Color</span><span class="p">.</span><span class="nf">TryParse</span><span class="p">(</span><span class="n">s</span><span class="p">,</span> <span class="k">out</span> <span class="n">color</span><span class="p">)</span> <span class="p">||</span> <span class="n">Color</span><span class="p">.</span><span class="nf">TryParse</span><span class="p">(</span><span class="s">$"#</span><span class="p">{</span><span class="n">s</span><span class="p">}</span><span class="s">"</span><span class="p">,</span> <span class="k">out</span> <span class="n">color</span><span class="p">))</span>
            <span class="p">{</span>
                <span class="k">return</span> <span class="k">new</span> <span class="nf">SolidColorBrush</span><span class="p">(</span><span class="n">color</span><span class="p">);</span>
            <span class="p">}</span>

            <span class="c1">// If string was not convertible, we return null</span>
            <span class="k">return</span> <span class="k">null</span><span class="p">;</span>
        <span class="p">});</span>
<span class="p">}</span></code></pre>
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<div class="sect2">
<h3 id="_step_2_setup_the_view">Step 2: Setup the View</h3>
<div class="paragraph">
<p>Our view will be made of one <code>TextBox</code> which has an <code>Ellipse</code> as the <code>InnerLeftContent</code>. This Ellipse will be painted using the converter.</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="rouge highlight"><code data-lang="xml"><span class="nt">&lt;TextBox</span> <span class="na">Watermark=</span><span class="s">"Type the color to parse (e.g.: red, green, blue, #FF112233)"</span> <span class="nt">&gt;</span>
    <span class="nt">&lt;TextBox.InnerLeftContent&gt;</span>
        <span class="nt">&lt;Ellipse</span> <span class="na">Fill=</span><span class="s">"{Binding $parent[TextBox].Text, Converter={x:Static conv:FuncValueConverters.StringToBrushConverter}}"</span>
                 <span class="na">Width=</span><span class="s">"20"</span>
                 <span class="na">Height=</span><span class="s">"20"</span>
                 <span class="na">StrokeThickness=</span><span class="s">"1"</span>
                 <span class="na">Margin=</span><span class="s">"2"</span>
                 <span class="na">Stroke=</span><span class="s">"Gray"</span><span class="nt">/&gt;</span>
    <span class="nt">&lt;/TextBox.InnerLeftContent&gt;</span>
<span class="nt">&lt;/TextBox&gt;</span></code></pre>
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<div class="admonitionblock note">
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<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
We use a binding to an ancestor using the <code>$parent</code>-syntax in this sample. See <a href="https://docs.avaloniaui.net/docs/guides/data-binding/binding-to-controls#binding-to-an-ancestor">[here]</a> for more about it.
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<div class="sect2">
<h3 id="_step_3_see_it_in_action">Step 3: See it in action</h3>
<div class="paragraph">
<p>In your IDE select <code>[Run]</code> or <code>[Debug]</code> to see the result in action. Try to change the value in the input box and see how it updates the result below.</p>
</div>
<div class="imageblock">
<div class="content">
<img src="_docs/result_03.png" alt="FuncValueConverter sample">
</div>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_related">Related</h2>
<div class="sectionbody">
<div class="paragraph">
<p>Avalonia has some really nice built-in <code>Converters</code> for you. Read more about  in the <a href="https://docs.avaloniaui.net/docs/data-binding/converting-binding-values">[Docs]</a>.</p>
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Last updated 2025-11-06 19:42:36 UTC
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